“The safety of the flying public is our top priority and we won’t allow the 787 to return to commercial service until we’re confident that any proposed solution has addressed the battery failure risks,” the FAA said in a statement Friday.

Ray Conner, president of Boeing Commercial Airplanes, met with Michael Huerta, administrator of the FAA, in Washington, D.C.

Boeing called the meeting “productive” and was encouraged by progress made during the meeting, the company said in a statement.

“Boeing has drawn upon resources from across the company and externally, pulling together teams of hundreds of experts and working this issue around the clock for the past several weeks. The company has been working closely with the FAA and other authorities throughout,” the company said.

The FAA grounded Boeing’s 787 on Jan. 16 after the lithium-ion batteries failed on two Dreamliners in incidents less than two weeks apart. Fifty 787s had been delivered to airlines at that time.

Sources told the Associated Press that Boeing is suggesting a battery fix that would increase the space between cells in the lithium-ion batteries. That proposal would mean keeping the 787s grounded at least until April.

FAA said on Friday it is reviewing Boeing’s proposal and will “analyze it closely.”

The National Transportation Safety Board is still investigating a Jan. 7 battery fire on a Japan Airlines 787. The NTSB is expected to release a preliminary report on the incident next month.